ntpd in ntp 4.2.8p10, 4.2.8p11, 4.2.8p12 and 4.2.8p13 allow remote attackers to prevent a broadcast client from synchronizing its clock with a broadcast NTP server via soofed mode 3 and mode 5 packets. The attacker must either be a part of the same broadcast network or control a slave in that broadcast network that can capture certain required packets on the attacker's behalf and send them to the attacker.
総合評価: CVE-2018-8956 は中リスク（50.9/100）。CVSS 深刻度は中。悪用される可能性が高い（EPSS 1.95%、83 パーセンタイル） 推奨対応: 影響資産を整理し、修補計画に組み込んでください。
リスクは変動します。再評価に基づき、本ページの表示内容を更新しています。
EPSS は日次で悪用されやすさの相対度合いを推定します。パーセンタイルは採点済み CVE の中での相対位置（高いほど相対的に深刻）を示します。
| # | 日付 | 旧 EPSS スコア | 新 EPSS スコア | Δ（新 − 旧） |
|---|---|---|---|---|
| 1 | 2025-12-28 | 1.31% | 1.95% | +0.65% |
| 2 | 2025-12-27 | 1.95% | 1.31% | -0.65% |
| 3 | 2025-12-15 | — | 1.95% | — |
EPSS の全履歴 （全 14 件）
この CVE の CVSS 指標。
| ベーススコア | バージョン | 深刻度 | ベクトル | 悪用しやすさ | 影響 | スコアの出典 |
|---|---|---|---|---|---|---|
| 5.3 | 3.1 | MEDIUM |
|
3.9 | 1.4 | [email protected] |
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
low | CVE-2018-8956 low priority: Debian including 2 source packages (ntp, ntpsec), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. | https://security-tracker.debian.org/tracker/CVE-2018-8956 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2018-8956 |
suse
|
low | CVE-2018-8956 severity low: SUSE including 16 source package names (ntp-4.2.8p15-4.10.1, ntp-4.2.8p15-48.30.1, …), 93 product×package rows across 67 product lines (HPE Helion OpenStack 8, Image SLES12-SP5-Azure-BYOS, … (67 product lines)): Fixed 93. | https://www.suse.com/security/cve/CVE-2018-8956/ |
ubuntu
|
low | CVE-2018-8956 low priority: Ubuntu including 1 source packages (ntp), 17 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 7, needs-triage 6, ignored 4. | https://ubuntu.com/security/CVE-2018-8956 |
| URL | タグ |
|---|---|
| http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00005.html | |
| http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00044.html | |
| http://www.ntp.org/ | Vendor Advisory |
| https://arxiv.org/abs/2005.01783 | Third Party Advisory |
| https://nikhiltripathi.in/NTP_attack.pdf | Third Party Advisory |
| https://security.netapp.com/advisory/ntap-20200518-0006/ | |
| https://tools.ietf.org/html/rfc5905 | Third Party Advisory |